Tolkien's densely populated fictional world is now the subject of a minutely-detailed 'family tree project'

More of the Rings: detail from the Family Tree Project website

I am a Tolkien fan. I reread Lord of the Rings every now and then; seeing the trailer for The Hobbit sent shivers down my spine; my daughter is called Merry, for goodness sake. But my devotion to Middle-earth pales before that of Emil Johansson, a photographer and chemical engineering student from Sweden, who has read "every book there is to read about Middle-earth" and who has spent years compiling a family tree of every character – every character! – in Tolkien's world.

Take a look: supreme god Eru Ilúvatar sits at the top, but dig a little further and you'll find out how, exactly, the Sackville-Bagginses are linked to the Bagginses, that Sam Gamgee and Rosie Cotton had 12 little hobbit children, and oh so very much more.

The project started when Johansson was 14 years old, on paper. "If I remember correctly I had just finished reading Tolkien's Unfinished Tales and I wanted to immerse myself even more in the world of Middle-earth. Doing a family tree became a natural step of trying to understand the world better," he says, admitting that "looking back, I probably had too much time on my hands".

It quickly developed from including just a few elves and men into a project with over 600 characters. Johansson put it online last week, and is now up to 703 characters, but believes there's still at least 100 to go. "I have most trouble adding the remaining hobbits. Tolkien really put a lot of effort into their genealogy," he says.

He's received a "massive flood" of feedback from Tolkien fans around the world since he launched The Lord of the Rings Family Tree Project – from encouragement to suggestions and corrections. "I depend on people doing this since my knowledge of Tolkien's world is fairly limited. If I had studied programming and not chemical engineering I might have programmed it to be a collaborative website instead," says Johansson, revealing that Aragorn is the Tolkien character to fascinate him the most. "Not so much Aragorn the king but his life as a ranger. I guess I feel that way because I always wanted to try living like that."